By Sharon Omahen
University of Georgia
What global warming will really do to farm crops isn't a speculative study for some scientists. On a tiny scale in Georgia, they're seeing the effects for themselves.
The Georgia Envirotron in Griffin, Ga., makes what-if studies come alive for University of Georgia and visiting scientists. They can see, among other things, how a simultaneous rise in temperature and carbon dioxide might affect many food crops.
"Using the Envirotron's controlled-atmospheric chambers, researchers can actually see how global warming will affect agriculture," said Envirotron manager Ian Flitcroft.
Flitcroft is an agricultural research engineer with the UGA College of Agricultural and Environmental Sciences.
Controlling temperature, humidity and light
Opened in 1998, the $1.26 million Envirotron allows researchers to study how a number of stresses affect plants. They're able to control temperature, humidity, carbon dioxide and light. And they can subject plants to the stresses of air pollutants and other atmospheric gases.
With indoor growth chambers, they study plants, pests and diseases in a precisely controlled environment. Greenhouses allow them to simulate field conditions.
UGA researchers are using the Envirotron's controlled environment chambers to look at Georgia-grown crops.
A team of UGA agricultural engineers is studying Georgia peanuts. They're looking at how rising temperatures affect peanut varieties grown here. They're also studying the effects of global warming on the viability of Georgia-grown peanut varieties."A group of UGA horticulturists is using the chambers to study blueberry fertilization," Flitcroft said. Chambers cut off from the rest of the world let the group control pollination. They can tell the differences between self-fertilization and cross-fertilization. And they can see how fertilization timing affects the quality of blueberries. The chamber temperature can be set to delay flowering until researchers are ready to begin an experiment. Then the temperature and day length can be manipulated to induce flowering, Flitcroft said.
Studying a host of crops
Two scientists from Mexico and one from South Korea are using the UGA facility to investigate crops grown in their countries.
"The Korean scientist is interested in cotton," Flitcroft said. "The Mexican researchers are looking at how rising temperatures will affect maize, soybeans and dry beans grown in their country."
UGA engineers are using the Envirotron, too, to test a computer model they've developed to simulate crop growth and to predict yield.
"They're using the growth chambers to see if the actual results match their model's predictions," Flitcroft said. "If the results prove the model effective, they can begin promoting the model (to farmers)."
Checking results in the Envirotron helps the researchers pinpoint parts of their model that may need improving, too.
Other scientists use the Envirotron as a testing ground for new crops. A visiting scientist from Iran is using the facility to predict how well sesame will grow in Georgia.
"He wants to determine at which temperatures it will grow best," Flitcroft said, "to see which varieties will grow best for conditions in Georgia where sesame currently is an unknown crop."
Trials of these projects should be completed by the end of June. The researchers will then begin compiling their data and documenting their findings.
"We try to schedule the test plots during the winter," Flitcroft said. "It is much less expensive to operate the Envirotron's chambers. Our power bill runs about $4,000 a month in the winter, compared to $10,000 a month in the summer."
(Sharon Omahen is a news editor with the University of Georgia College of Agricultural and Environmental Sciences.)